Humphrey graduated from The Chemical Institute in Barcelona, received his master's degree from the University of Toronto, and his doctorate in mechanical engineering from Imperial College London.

His research and teaching focused on experimental, theoretical and numerical investigations of flow, heat and mass transfer phenomena, especially in relation to biomedical and biological systems. He published more than 135 journal papers and 100 refereed conference papers, and was active in various professional societies, including the American Society for Mechanical Engineers, in which he was a fellow. He was the founder of the biennial International Symposia on Sensors and Sensing in Biology and Engineering and a co-founder of the biennial International Symposia on Turbulence and Shear Flow Phenomena.

Translation of his research: He was trying to understand how spiders sensed the right breeze conditions to float the farthest on their silken threads. He and a team of researchers wanted to figure out how to replicate and adapt those sensors for human use – to sense danger or other factors in the surrounding environment, including earthquakes. He was studying tiny sensors in other arthropods, such as cockroaches and crayfish.

Humphrey was a warm and enthusiastic person, according to those who worked closely with him. "Pepe quite simply devoted himself to making things better," colleague George Gillies said. "He loved the process of bringing people together to create new research projects, and he took great joy in seeing those relationships develop. He was a tireless advocate for the Engineering School and the University in general, and he took every opportunity to promote the welfare of students."

"Pepe was a true gentleman and a scholar," said Hossein Haj-Hariri, chair of mechanical and aerospace engineering at U.Va. "His approach to his research, his teaching and especially his approach to his illness, set an example to everyone who had the good fortune to know him.

"He kept up with his research, continued to meet with his students, published papers and continued to live his life to the highest standard right up to the end. He will be missed."

Prior to his arrival at U.Va., he held a faculty position at the University of California at Berkeley, followed by a position at the University of Arizona, where he chaired the Department of Aerospace and Mechanical Engineering. He also served as dean of engineering at Bucknell University.

He is survived by his wife, Sarah Humphrey; three daughters, Luisa Humphrey of Cali, Colombia, Fiona Stonehouse of Liverpool, England and her husband, Paul, Kaite Lynch of Charlottesville and her husband, Tracy; a brother, Peter Humphrey of British Columbia, Canada; a sister, Margaret Humphrey of Melbourne, Australia; two nephews; a niece; and two grandchildren. A memorial service is planned for March 27 at 11 a.m. at St. Paul Memorial Church in Charlottesville.